Printing medium.



' as an agent for overcoming the inherent UNITED STATES PATENT iorrion PAUL CHAltLES AND-'STEPHAN FAUJAT, OF FRANKFORT-ON-THE-MAIN, GERMANY, ASSIGNORS TO JOE LIVINGSTON, OF 'FRANKFORT-ON-THE MAIN, GERMANY.

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Specification of Letters Patent.

manna Aug. 3, 1909.

Application filed August 22f1906. Serial No. 381,582.

Printing Medium, of which the following is a specification.

The invention relates to a printing med1um or color having a gelatin base, and

more particularly to colors of this character to be employed in printing from intaglio forms.

In printing from intaglioforms, such as photo-engravings, copper-engravings, etched plates and the like, with a color medium having a gelatin base in which the excess of printing medium is removed from the sur face of the plate or form by means of a doctor or wiper, it is customary, in order to preventthe gelatin medium from adhering to the surface of the form, to cover the latter with oil. It was found, however, that the oil entering the depressed or intagliated portions of the form caused the ink to be removed to a greater or lesserdegree therefrom, also with the result that the printed copy was either too faint or irregular in color and tone. In an endeavor to obviate this difficulty it has been proposed to add to the gelatin printing medium a solution of ox gall, but it was found that if an excess of the ox gall solution were employcdfithe printing medium could not. be uniformly removed from the surface of the plate by the doctor, and the impressions taken from the form were blurred, smeared about the edges and otherwise imperfect. On the other hand, if too little of the ox gall solution were employed, the coagulated gelatin color ing medium adhered to the engraved orin tagliated lines of the form .in the printing operation and it was impossible to obtain a uniform impression or print. Hence the ox gall is very unsatisfactory and unreliable difficulties ofintaglio printing with gelatin color mediums. We have found, however. that by employing a fatty material mixed witlrthe gelatin color, the gelatin medium could be thoroughly and effectively removed from the surface of the form before the printing operation, leaving the material in the intagliated lines in the best possible condition to be transferred smoothly and uniformly to the printed surface. To produce an intimate admixture of the fatty material with the gelatin base, drying oils, waxes, spermaceti, or the like, are preferably saponified or .emulsified and mixed in suflicient quantity with the gelatin dissolvedin a little water, inorder to produce a comparatively thick, smooth and pliant color medium. The proportion of fatty matter depends, of course, upon the character or properties of thefat.

Water, 20 grams of linseed oil, 5 grams of soap, and between 1 and 3 grams of coloring matter. A printing medium possessing the compositionmentioned may be removed by the doctor or wiper, without any tendency to flow or smear, or, on the other hand, to draw out in thread-like form, sothat the medium'is completely cleaned from the surface of the plate and'is absolutely undisturbed in the 'intagliated lines, and the im-' pression, produced by the printing operation, is smooth, even and uniform, even in the softest half-tone effects. The addition of the oil to the gelatin printing medium renders the prints or impressions much softer in effect and also prevents the troublesome rolling, which is a recognized defect of all gelatin prints, in dry weather.

What. we claim is:

l. A printing medium for use with intaglio forms, comprising thev following 111' gredients in substantially the proportions indicated; a gelatin base 10 parts, water 10 parts, coloringmaterial 1 part, and a fatty constituent 20 parts.

2. A printing medium for use w th n taglio forms, comprising thefollowmg 1ngredients in substantially the proportions indicated; a gelatin base 10 parts, water 10 parts, coloring material 1 part, and a soapy material 20 parts.

3. A printing medium for use w th mtaglio forms, comprising the f0llow1ng 1ngredients in substantlally the proportions indicated; a gelatin base 10 parts, water 10 parts, coloring material 1 part, and an emul- A suitable mixture, for example, consists of 10g'rams of gelatin, 10 grams of meme 4. A printing medium foruse with in- 1 in presence of two witnesses, this eleventh 'teglio forms, comprising the following inday of August 1906. gredients in substantially the proportions PAUL CHARLES indicated a gelatin 10 parts water 10 parts I coloring xhaterial 1 part, an hi1 20 parts, and (DTEPHAN FAUJAT' a soap 5 parts. Witnesses:

In testlmony, that we claim the foregoing CARL WEIHE,

as ourinvention, We have signed our names FRIEDRICH QUEHL. 

